Yield Response of African Rice Genotypes to Mycorrhizal Fungi and Rhizobium Inoculation

Aims: A short term field study was conducted to investigate the yield performance of selected African rice genotypes inoculated with biofertilizers.   Study Design: A randomized complete block design laid out in a split-plot arrangement was used to evaluate response of yield components and grain yield of some selected African rice genotypes will be to mycorrhizal fungi and rhizobium inoculation. Place and Duration of Study: The study was conducted at the Teaching and Research farm of the Federal university of technology, Akure Ondo state, Nigeria during the 2013 planting season. Methodology: The study was laid out in a split plot arrangement in Randomized Complete Block Design (RCBD), with mycorrhizal fungi, rhizobium inoculation and control in the main plot, while genotypes (N-U-1, N-U-8, WAB 56-104, OFADA GR and MOROBEREKAN) were in the sub-plot and treatments were replicated thrice. There were three main blocks, each block consist of 15 sub-plots with a size measurement of 2m x 1m and inter sub-plot spacing of 0.5m in between plots. A total of 50 plants were raised per sub plot. Transplanted seedlings were planted with the soil slurry containing rhizobium and mycorrhizal fungi inoculum into planting holes in the field at two seedlings per stand, according to their respective plot at a spacing of 25cm x 25cm. Yield component data collected include; number of days to 90% maturity, number of days to 50% flowering; plant height at maturity, number of primary tillers per plot, number of grains per panicle, number of panicles, number of filled and unfilled spikelet, weight of 1000 filled grains and grain yield per plot.  Results: Result showed significant (P<0.05) single and interactive effect of rhizobium and mycorrhizal fungi inoculation on rice yield and yield components. 61.4% increase in grain yield was observed in rhizobium inoculated genotypes when compared to 37.4% increase in mycorrhized genotypes and the un-inoculated control. WAB56–104 and N-U-8 had the best interactive response amongst genotypes inoculated with rhizobium while genotypes WAB56-104 and MOROBEREKAN responded better amongst mycorrhized genotypes in relation to yield components. Conclusion: The results from this study indicate that African rice genotypes differ in grain yield response and host specifity when inoculated with mycorrhizal fungi and rhizobium inoculums. However, inoculating specific African rice genotypes with mycorrhizal fungi and rhizobium can positively influence their grain yield and yield component development and this could play an important role in improving African rice productivity.